L-shaped mineral cutter pick



Feb. 18, 1969 PRQCTbR 3,428,364

L-SHAPED MINERAL CUTTER PICK Filed Feb. 2, 1967 Sheet of 2 S- E. PROCTOR L-SHAPED MINERAL CUTTER PICK Feb. 18, 1969 Z of 2 Sheet Filed Feb. 2, 1967 United States Patent 3,428,364 L-SHAPED MINERAL CUTTER PICK Sidney E. Proctor, High Wycombe, England, assignor to Austin Hoy and Company Limited Filed Feb. 2, 1967, Ser. No. 613,549 Claims priority, application Great Britain, Mar. 18, 1966,

12,136/ 66 US. Cl. 299-91 Int. Cl. E21c 13/00 9 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to forward attack coalcutter picks and to a combination of cutter picks and pick boxes.

It has heretofore been proposed to cut coal by means of shearer drums having forward attack cutter picks mounted thereon. Since a shearer drum must cut clearance for itself as it advances into the coal, it is generally necessary to provide the outer end of the drum with radial-type picks which are angled over outwardly to provide clearance for the end of the drum. If the latter picks are mounted turned about a drum radius, considerable rubbing takes place as the picks do not fully cut clearance for themselves, having been designed for forward attack cutting.

It has also been proposed to mount these picks turned about a drum tangent whereby they can cut clearance both for themselves and for the drum. However it has been found that this method is not wholly satisfactory in practice.

An object of the present invention is to provide a cutter pick that is suitable for use for forward attack cutting and will also, when mounted in a pick box at one end or side of a drum or chain, cut clearance for itself and that part of the drum or chain on which it is mounted.

The present invention is a forward attack coal-cutter pick comprising a blade portion and a shank extending substantially at right angles thereto, the shank-remote end of the blade portion having a cutter tip which is wider than the blade portion and transverse thereto.

Preferably the blade portion and the shank have a common plane of symmetry and the cutter tip is also symmetrical about this plane.

The present invention is also in combination a coalcutter pick and a pick box therefor and which i carried by a shearer drum or cutter chain link, said pick comrising a blade portion and a shank extending substantially at right angles thereto, the shank-remote end of the blade portion having a cutter tip which is wider than the blade portion and transverse thereto, and said pick box having a bore or recess therein into which said shank is fitted for locking engagement, to extend transversely of the direction of movement of said box in a cutting operation.

Preferably the blade portion and the shank of the pick have a common plane of symmetry and the cutter tip is also symmetrical about this plane, whereby the pick may be used, in conjunction with pick boxes suitably positioned on a cutter chain, with the shank lying to the left or to the right of the direction of the relevant cutting movement.

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Preferably also the pick box has a groove or recess in the surface adjacent the pick and the pick has shoulders fore and aft of the shank which engage in said groove or recess.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a side elevation of a pick according to the present invention;

FIG. 2 is an end view of a chain link, pick box and the pick of FIG. 1; and

FIG. 3 is a perspective view of the chain link, pick box and pick.

Referring to the drawings, a coal-cutter pick comprises a blade portion 10, having a cutter tip 11 which is wider than the blade portion, and a mounting shank 12 extending substantially at right angles to the blade portion 10. A bayonet pin 13 is resiliently mounted in a bore in the shank and the pick has a further bore 14 at the root of the shank.

The pick is mountable in a pick box 16 (see FIG. 2) and the bore 14 is provided for engagement by an extraction tool or lever. The box 16 has a central rectangularsection recess or bore 17 for reception of the shank 12 and a groove 18 for reception of shoulders 19 of the pick thereby to locate the pick firmly in the pick box. The groove and shoulders 18 and 19 respectively serve to locate the pick both fore and aft of the shank portion to give support to the pick and to take some of the twisting strain from the shank.

Bayonet slots 20 having inclined lead in surfaces are provided in opposed side walls of the recess 17 and are disposed so that the shank of the pick can be held in looking engagement in the recess with bayonet pin 13 resiliently engaged in slots 20. Of course, the shank of the pick could be held in locking engagement in the recess by any other suitable means.

In this embodiment of the invention the pick box is welded to the link 19 of a coal-cutter chain, however, it will be clear that the pick boxes for picks according to the present invention may alternatively be welded to a shearer drum.

An advantage of this invention is that the tip is symmetrical about the plane of symmetry of the blade portion and the shank and therefore, varying pick-positions across the chain can be obtained by varying the positioning of the pick box on the base of the chain using only one type of pick.

I claim:

1. In a mineral-cutting apparatus wherein mineralcutter picks are mounted in pick boxes carried by a carrier member for movement in an endless path, the combination comprising a mineral-cutter pick including a shank and a blade portion unitary with said shank and substantially at right angles to the shank, which blade has a cutting tip wider than said blade in a direction parallel to the axis of the said shank and facing in a direction transverse to the axis of said shank, and a pick box having an opening accommodating said shank so that the shank is surrounded on all sides by the box, said and pick box having interengaging abutment surfaces preventing rotation of the pick about the axis of said shank and means releasably locking the shank against axial movement in said opening.

2. The combination as set forth in claim 1, wherein said interengaging abutment surfaces comprise side surfaces of said shank and said opening, the shank and the opening being of non-circular cross-section.

3. The combination as set forth in claim 2, wherein the shank and the opening are of rectangular cross-section.

4. The combination as set forth in claim 2, wherein said interengaging abutment surfaces also comprise the sur- 3 faces of interengaging parts on the adjacent sides of the blade and the box.

5. The combination as set forth in claim 4, wherein said interengaging parts comprise shoulders on said blade fore and aft of said shank and walls of a groove in the box intersecting an end of said opening, which groove receives said shoulders.

6. The combination as set forth in claim 1, wherein said interengaging abutment surfaces comprise at least one shoulder on the blade and walls of a groove in the box accommodating said shoulder.

7. The combination as set forth in claim 6, wherein the groove intersects an end of said opening and the blade has an aforesaid shoulder on each side of the opening.

8. The combination as set forth in claim 1, wherein said releasably locking means comprises a resiliently displaceable pin in said shank and a bayonet slot in the box, which slot contains the pin.

9. The combination as set forth in claim 1, wherein the blade and the shank have a common plane of symmetry and the cutting tip is also symmetrical about this plane.

References Cited UNITED STATES PATENTS 501,795 7/1893 Legg et al. 29991 X 1,019,251 3/1912 Hess 29987 2,916,275 12/1959 Bruestle et al 29992 3,075,755 1/1963 Funke et al. 2999'1 X FOREIGN PATENTS 154,649 1/ 1904 Germany.

ERNEST R. PURSER, Primary Examiner. 

